its all about weight for me.thats what puts me off buying an x line brush.
its ok using a heavier brush when cleaning bog standard houses with easy to reach windows.no problems but i have very few properties like these on my round.loads have awkward windows above connys/extensions,3 storey,velux etc and using heavier brushes makes a massive difference on the end of an xtreme pole.
today ive been cleaning mostly 3 bed semis(4 weekly work) with lots of these types of windows often extending my pole to the full 25ft to reach them.ive been using an xtreme medium mixed.light as a feather and scrubs well for such a light brush.it was virtually effortless poling with this brush.
i switched once to a flocked supreme for a fairly large 5 bedder(8 weekly job)as it has a fair few leaded windows and pretty dirty due to frequency and being surrounded by large trees.